The goal of this project was to develop a small, low-power camera system suitable for integration as a CubeSat payload. Three prototypes were developed, resulting in a flexible dual-camera architecture for many kinds of on-orbit imaging needs.
This project was intended to satisfy the requirements for the Canadian Satellite Design Challenge, with the goal of flying it as a payload on SFUSat’s entry to the competition. The competition requires that the satellite provide imaging capability that can be scheduled from the ground.
As an extension to these requirements, the team decided to develop a dual-band system targeting the visbile and NIR bands. With the capability to image in both of these bands, we can create data products such as NDVI, which are used to determine health of crops.
- 40x40 km swath at 400 km orbit
- Low power
- Visible and NIR imaging capability
- On-orbit image processing
- Easy to assemble
1. Swath Width
The swath width of the camera system is defined by its lens selection and the specifics of the image sensor. With a low budget and a small team, sensor selection was limited to available components on electronic component distributors such as Digi-Key and Mouser. This excludes sensor manufacturers such as Sony, who do not make their devices easy to purchase in small quantities. Availability of sensor development boards was also desired, as it would mean we could prototype with the sensor without the expense and effort of building a PCB for it. With these constraints in place, we derive some more requirements and constraints.
- Image sensor available from common distributor
- Image sensor or sensor family available on inexpensive development board
- Resolution availability between 2 MP and 5 MP
Lens selection was handled by other members of the team, but generally followed these requirements:
- Vacuum-rated lens preferred
- Minimal moving parts - fixed aperture preferred
- Focus at infinity
- CS mount or M12 mount
- Robust lens design rated for high vibration environments
2. Low Power
With CubeSats, low power is always preferred. While it is possible for the host satellite bus to include deployable panels, it is overall much simpler to specify low-power subsystems if they are available. There are many components to a good low-power payload strategy, but the primary way we decided to tackle this was to ensure that the camera can be completely powered-down by the satellite’s onboard computer when not in use. From this, several requirements can be derived:
The module shall:
- provide capability for host satellite to turn off power from the camera module
- provide status reporting for whether it is safe to power-down the camera
- include non-volatile image storage
- provide the ability able to retrieve images from non-volatile memory
- operate over a single 3.3 V supply
- consume no more than 1 W when in use (imaging)
This page is under construction.